The exemplary embodiment relates to a biocompatible polymer composition which includes an antioxidant, such as a xanthone. It finds particular application in forming dialysis membranes, and will be described with particular reference thereto. However, it is to be appreciated that the present exemplary embodiment is also amenable to other like applications.
Currently, a variety of surface modification techniques are available to produce biocompatible materials. They include polyethylene glycol grafting, albumin coatings, phospholipid mimicking surfaces, plasma treatments, fluorination, modification using anti-platelet agents like prostacyclin and fibrinolytic agents, and heparinizing the surface. Anti-bacterial surface treatments have also been proposed.
However, these existing biocompatible materials may only offer a few additional properties over their basic functional requirements. Medical applications such as implants, hemodialysis, peritoneal dialysis, and other similar applications, would benefit from multiple properties, such as anti-bacterial, anti-viral, anti-oxidative, and/or anti-inflammatory properties in order to maintain a better quality of life for a patient.
As an example, hemodialysis is primarily used to provide an artificial replacement for lost kidney function by filtering impurities from the blood. However, there are problems associated with hemodialysis, such as an increase in oxidants in the blood and inflammatory responses due to long term exposure of the blood to a synthetic polymer surface. At this time, in order to obtain relief, a dialysis patient generally undergoes supplemental drug therapy which adds a significant cost to the overall dialysis costs.
Recently, concerns have been expressed over a series of pathologic events deriving from reactive oxygen species (ROS). This is so called “oxidative stress” which is further exacerbated during dialysis due to the reduction of antioxidants and interactions between blood and the dialysis membrane. Oxidative stress is the result of an imbalance between pro- and antioxidant molecules. Some hemodialysis membranes now utilize vitamin-E in order to provide anti-oxidant properties. However, inflammatory responses still occur with such membranes.
The exemplary embodiment provides a biocompatible polymer composition suited to use in hemodialysis as a membrane for insertion into a dialyzer filter which overcomes the above-referenced problems, and others.